Trials and Tribulations
All clinical trials are not created equal – but if prospective registration is enforced, questionable results become easier to spot
Roisin McGuigan |
Clinical trials are a linchpin of translational science. But to be useful to the research and medical communities, they need to be accessible and trustworthy. A recent study conducted in Finland found that of 113 clinical trials approved in 2007 by the research ethics committee for the region of Helsinki and Uusimaa, 69 percent were prospectively registered, and 64 percent were published – leaving a significant proportion that weren’t. In 23 trial protocols, a primary outcome was not defined, and discrepancies were found in primary outcomes in 16 of the registered trials, and nine that were published (1).
The features associated with registration and publication without discrepancies in the primary outcomes included those studies that involved a drug or biologic, larger samples sizes, and multicenter studies. Differences between the protocol and the publication were more common in unregistered trials – and only one published paper mentioned any change. The authors recommend that original protocols and any amendments should be made publicly available in all cases.
Although many countries and organizations already have policies regarding clinical trial regulation and transparency, it is by no means universal – as demonstrated by the work of the WHO International Clinical Trials Registry Platform (2). A recent analysis in the New England Journal of Medicine also found that roughly a third of trials registered on clinicaltrials.gov were registered late – a practice that prevents information on the trial from being available from its outset and making it more difficult to identify selective reporting (3).
“Journal editors, regulators, research ethics committees, funders, and sponsors should implement policies mandating prospective registration for all clinical trials. Only with accessible, complete information can interventions be adequately evaluated for patient care,” concluded the authors.
- AW Chan et al., “Association of trial registration with reporting of primary outcomes in protocols and publications”, JAMA, [Epub ahead of print] (2017). PMID: 28892118.
- World Health Organization, “International Clinical Trials Registry Platform (ICTRP)”, (2017). Available at: www.who.int/ictrp/en/. Last accessed October 3, 2017.
- DA Zarin et al., “Update on trial registration 11 years after the ICMJE policy was established”, N Engl J Med, 376, 383–391 (2017). PMID: 28121511.